Rubio beat millionaire developer Carlos Beruff, the only major GOP candidate to stay in the race after Rubio decided to run for re-election two days before the deadline to make the ballot. He had said for months he wouldn't run again no matter what happened in the presidential race.

The general election in Florida, the largest swing state in a presidential year, is expected to be critical to Democratic hopes to recapture the majority in the Senate. Republicans are defending 24 seats in the 2016 election, compared to 10 Democratic seats that go before voters. The GOP currently holds a total of 54 seats, while Democrats and two independents who usually vote with them have 46.